chore: reformat with gofumpt (#109)

* Reformat with gofumpt

* Suppress issue about laxer perms than 0600

---------

Co-authored-by: Joel Kamp <joel.kamp@docker.com>

pkg/mirror/mirror.go

@@ -137,7 +137,7 @@ func SaveReferrers(manifest *attestation.AttestationManifest, outputs []*oci.Ima
 		if err != nil {
 			return err
 		}
-		//otherwise we end up with the detected platform, though I'm not sure it matters
+		// otherwise we end up with the detected platform, though I'm not sure it matters
 		attOut.Platform = &v1.Platform{
 			OS:           "unknown",
 			Architecture: "unknown",

pkg/mirror/mirror_test.go

@@ -43,7 +43,6 @@ func TestSavingIndex(t *testing.T) {
 }
 
 func TestSavingImage(t *testing.T) {
-
 	outputLayout := test.CreateTempDir(t, "", "mirror-test")
 
 	img := empty.Image